Down-hole gas separation methods and system

ABSTRACT

A method and apparatus for separating of gas from liquids in a wellbore, the apparatus enabling the receiving of wellbore fluids into two or more production separation chambers, operating in parallel. The apparatus further enabling the receiving of production separation chamber fluids into a production pipe through a thief jet port disposed in a lower chamber beneath the production separation chambers. The apparatus further enabling extraction of bottom hole gas fluids in the wellbore from under the two or more production separation chambers and disposing the gas fluids back into the wellbore above the two or more production separation chambers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/066,201 of filing date Oct. 8, 2020. U.S. application Ser. No.17/066,201 benefit of U.S. Provisional Application No. 62/912,588 offiling date Oct. 8, 2019.

TECHNICAL FIELD

Disclosed herein are improvements to down-hole gas separation method,apparatus, and system.

BACKGROUND ART

In the current state of the art, pumping fluids in low pressurewellbores has the propensity to produce large pockets of gas, over 20foot columns, and gas-lock a pump, preventing production. In essence,fluid is pumped up from a fluid retrieving section of the bottom holeassembly. As the pumped fluid is “sucked” up the production tube, gasseparates from the fluid and bubbles to the top of the fluid column.Eventually, enough gas separates and rises to the top of the fluidcolumn that a pump becomes gas locked and can no longer pump. The pumpmust stop pumping and wait for the gas to dissipate before it can resumepumping.

There is a strong need to separate gas from production fluids in thewellbore so that only liquids are pumped, thus preventing gas locking ofthe well and providing more liquid returns from the pump.

BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS

FIG. 1 illustrates a side cross-section view of an example of a 2-1 unitattached beneath a Pressure Loss Cylinder having a top make-up.

FIG. 2 illustrates a side cross section view of an example of aconfigured gas separator tool having a top Pressure Loss Cylinder, twostacked 2-1 units, and a feed cylinder with bottom make-up. A packer isalso located around the tool.

FIG. 3 illustrates a side cross section view of an example of a 4-1 unitto be attached beneath a Pressure Loss Cylinder.

FIG. 4 illustrates a side cross section view of an example of a feedcylinder with a particulate filter.

DISCLOSURE OF THE INVENTION

FIG. 1 illustrates a side cross-section view of an example of a 2-1 unitattached beneath a Pressure Loss Cylinder having a top make-up.

FIG. 1 illustrates a cut-away view detail of a pressure loss cylinder inan upright, vertical position of a gas separation system. In thisexample, shown is an assembly of a pressure loss cylinder 100 atop twostacked production separation cylinders 200, 300 stacked on a bottomcylinder 400. The production separation cylinders are isolationchambers. In one example, a make-up 101 is attached to the top ofpressure loss cylinder 100. In this example, there is a pipe 1 having aproduction tube 2 running vertically inside the pipe 1, along thelongitudinal vertical axis of the pipe 1. The production tube 2 and thepipe 1 form annular regions 103, 203, 303, 403 between the exterior ofthe production tube 2 and the interior wall of the pipe 1. The interiorannular regions 103, 203, 303, 403 between the production tube and thepipe, in this example, is divided into four stacked chambers 100, 200,300 400 along the longitudinal vertical axis of the pipe and productiontube (which, in one example, is also a pipe). The topmost chamber, alsocalled a cylinder in this example, is called the pressure loss cylinder100. Pressure loss cylinder 100 serves to accumulate formation fluids,which, in one example, are isolated formation fluids that have beentransported to and dumped into pressure loss cylinder 100. In oneexample, the combination of pipe 1 enclosing production tube 2 is calleda shrouded production pipe, with pipe 1 being called the shroud.

In one example, the cylinders are isolated by annular rings 150, 250 350disposed vertically between the pipe 1 and production tube 2, forming abarrier to control the vertical flow between the annual regions 103,203, 303.

In the pressure loss cylinder 100, there are orifices or openings 102 inthe wall of the pipe 1. These openings 102 open the interior annularregion 103 to the annular region that is between the exterior of thepipe 1 and the walls of the well bore. In one example, one or moreopenings 102 are positioned near the top of the pressure loss cylinder100 and another set of one or more openings 104 are positioned near thebottom of the pressure loss cylinder 100. The top openings 102 is/arefor gas exhaust. The bottom openings 104 is/are for gas-removed liquidsto exhaust. This delivery method puts liquid in the well bore annulusbelow the gas and causes upward lift.

There are also transport tubes 4, 5 6 that run vertically in theinterior annular regions between the production tube 2 and the pipe 1.One or more transport tubes 4 have an end positioned to terminate aboutmidway vertical length of the pressure loss cylinder 100. These one ormore transport tubes 4 run down through the bottommost cylinder 400,where the other end of the transport tube 4 is positioned so it may beconnected to additional separation cylinders below (not illustrated inthis FIG. 1 ). Another set of one or more transport tubes 5 have an endpositioned near the top of the pressure loss cylinder 100. These one ormore transport tubes 5 run down to the next lower cylinder 200 of thefour cylinders that are illustrated, with the other end of the transporttube 5 positioned to open into the top of that next lower cylinder 200.The next lower cylinder 200 is called a production cylinder.

The next lower cylinder 200, along with the next lower cylinder 300,also a production cylinder, (the second and third and fourth cylindersfrom the top in this illustration) are together called a 2-1 unit 500. A2-1 unit 500 is also called a For the two production cylinders of the2-1 unit, another type of transport tube 6, also called a feed tube, hasone open end positioned at the bottom of the upper cylinder 200 of the2-1 unit. Transport tube 6, in this example as illustrated, runs insidethe annular region between the production tube 2 and the pipe 1. Thetransport tube 6 runs vertically downward into the bottommost fourthcylinder 400, where the other end of transport tube 6 is positioned. Inthis example as illustrated, the lower end of transport tube 6 openswithin the fourth cylinder. Notice that transport tube 4 goes throughannular space of the fourth cylinder 400, but does not open into theannular space. Instead, transport tube 4 traverses downward to have theoption of adding, stacking, another 2-1 unit or units beneath thisfirst, illustrated 2-1 unit 500. In this positioning of transport tube4, the lower end of transport tube 4 would open into the topmostcylinder of another 2-1 unit (not illustrated in this FIG. 1 , shown inFIG. 2 ).

In transport tube 6 there is a hole or orifice or opening 61, positionedtowards the bottom of the lower cylinder 300 of the 2-1 unit 500. Holeor orifice or opening 61 is called a feed tube port.

In each of the two cylinders 200, 300 of the 2-1 unit 500, in oneexample, there are orifices or openings 202, 204, 302, 304 in the wallof pipe 1. These openings 202, 204, 302, 304 open the interior annularregions to the annular region that is between the exterior of the pipeand the walls of the well bore. In the example, as illustrated, one setof one or more openings 202, 302 are positioned near the top of each ofthe two cylinders of the 2-1 unit 500. In the example, as illustrated,there is another set of one or more openings 204, 304 that arepositioned lower, beneath the first set of open or more openings 202,302.

The production tube 2 runs in bottommost cylinder 400 and has an orificeor opening 10 positioned in cylinder 400. This orifice or opening 10 iscalled a thief jet.

In this structural configuration, the two gas separator cylinders 200,300 of the 2-1 unit 500 share a thief jet (10). Thus, two cylinders feedone thief jet.

In operation, a gas-liquid mix of fluids enter openings 304 of the lowercylinder 300 of the 2-1 unit. If some degassing occurs, and there aretwo sets of one or more openings 302, 304 vertically offset in the lowercylinder 300 of the 2-1 unit 500, then the upper set of one or moreopenings 302 will preferentially outflow the gas that is accumulating inthe lower cylinder 300 of the 2-1 unit 500. The lower set of one or moreopenings 304 will preferentially be the inflow of gas-liquid mix offluids from the wellborn annulus into the cylinder annulus 303.

Since the production tube 2 is drawing negative pressure by the wellpump, fluids will flow into the transport or feed tube 6 orifice 61 nearthe bottom of the lower cylinder 300 of the 2-1 unit 500. Liquids willfall into the bottommost fourth cylinder 400 and be drawn into the thiefjet 10. Likewise, the upper cylinder 200 of the 2-1 unit 500 willoperate in a similar manner, feeding liquids into the top end oftransport tube 6 that is positioned near the bottom of the uppercylinder 200 of the 2-1 unit 500. By positioning and arranging into the2-1 unit configuration, the intake cross-sectional area is doubled sothat the fluid velocity required to supply liquids to the thief jet 10is halved.

Gasses will exit the top end of transport tube 5, which is positionednear the top of the pressure loss cylinder 100, allowing the gas tofurther exit through top openings 102 of the pressure loss cylinder 100.In one example, reduced-gas or gas-free liquids accumulate in pressureloss cylinder 100 and are returned to the wellborn above the one or more2-1 units 500 that are stacked below the pressure loss cylinder throughone or more orifices 91 that are positioned near the bottom of thepressure loss cylinder 100. In one example, those sets of one or moreopenings 104 that are positioned near the bottom of the pressure losscylinder 100, these ports or openings 104 are restricted to create acontinuous fluid column in the pressure loss cylinder 100.

Thus, double the flow rate is accomplished by stacking two gas separatorcylinders, drawing in fluids in parallel. At the same time, the pressureloss cylinder serves to manage expelling of gas (like a chimney effect),making use of as much vertical distance as practical. Likewise, thefluids are provided with a long downward path to provide more time forthe gas to separate and liquid to go to the bottom. This effectivelengthening of the vertical fall distance is aided by placing a singlethief jet 10 at the very bottom of the three cylinder stack (the 2-1unit of two cylinders 200, 300 and the bottom cylinder 400 containingthe thief jet 10).

In one example, there is only one pressure loss cylinder on eachdownhole separator tool and the pressure loss cylinder is positioned atthe top, above all other separator cylinders. In one example, multiple2-1 units are deployed under the pressure loss cylinder, stackeddownward along the production tube. In one example, only the topmost 2-1unit has a pressure loss cylinder above it (for example, directly).

In one example, the pressure loss cylinder has a length of approximatelyeight feet (8′). In one example, the lengths of the production cylindersvary.

FIG. 2 illustrates a side cross section view of an example of aconfigured gas separator tool assembly 1000 having a top Pressure LossCylinder 100, two stacked 2-1 units 500, 501, and a feed cylinder 600with bottom make-up 601. A packer 701 is also located around the tool1000. The packer 701 is attached towards the bottom of the feedcylinder, to be deployed in the wellborn annulus. This indicates thatthe fluids in the wellbore annulus above the packer 701 are isolatedfrom the fluids in the well bore annulus below the packer 701, exceptthrough the circuitous route through the 2-1 units 500, 501 through thethief jets, to meet in the production tube.

In one example, the overall length of the tool assembly 1000 issixty-six feet (66′).

FIG. 3 illustrates a side cross section view of an example of a 4-1 unit5000. In one example the 4-1 unit 5000 is placed where a 2-1 unit wouldbe disposed in a stack (eg, between a top pressure loss cylinder and afeed cylinder). In this example configuration, four production cylinders5100, 5200, 5300, 5400 (instead of two) share (supply) a common thiefjet 10. In one example, the length varies. A series of feed tube ports5061 in feed tube 5006 are positioned near the bottom of each of thefour production cylinders 5100, 5200, 5300, 5400.

In one example, not illustrated, multiple 4-1 units are stacked down theproduction tube having a selected total length and a selected individuallength. In one example, the length of each 4-1 unit (or 2-1 unit, if 2-1units are used instead or if a combination of 4-1 units and 2-1 unitsare used) has a selected pattern of lengths of each. In one example, thelengths are the same for each type (4-1 unit, 2-1 unit) used.

FIG. 4 illustrates the use of a feed cylinder assembly 6000 beneath thebottommost production cylinder or unit. In this example, feed cylinderassembly 6000 is separated vertically into two chambers or cylinders6100, 6200. A collecting tube 6004 extends into two chambers 6100 and6200 of the feed cylinder assembly 6000. In one example, a block 6050 isdisposed, preventing direct flow from collecting tube 6004 intoproduction tube 2, for example when the same physical pipe is used forproduction tube 2 and the collection tube 6004. In one example, thechambers or cylinders 6100, 6200 are partially isolated from each otherby an annular ring 6150, disposed vertically between the pipe 1 and thecollecting tube 6004, forming a partial barrier to control the verticalflow between the two chambers or cylinders. In one example, smallorifices or tube stubs 6051 are disposed in the annular ring 6150,allowing some fluid flow from chamber or cylinder 6200 into chamber orcylinder 6100.

In one example, the bottom of chamber or cylinder 6200 has a make-up forconnection to other fluid pre-processing apparatus. In one example, thebottom of chamber or cylinder 6200 is open to the well bore forreceiving or drawing fluids.

In one example, upper chamber 6100 has an orifice 6005 in the tube 6004and the lower chamber 6200 has several smaller orifices 6006 in the tube6004. In one example, orifice 6005 is vertical elongate capsule shaped.Small orifices 6006 allow fluids to pass from the lower chamber 6200 tothe upper chamber 6100. The lower opening of transport tube 4 of thebottommost production cylinder or unit opens into the upper chamber 6100of the feed cylinder assembly 6000 for receiving production fluid fortransport to a pressure loss cylinder 100 at the top of the tool (notillustrated in this figure). The production tube 2 is blocked at thebottom of the bottommost production cylinder or unit, block 6050.Production tube 2 does not directly communicate with feed cylinderassembly 6000 and does not directly communicate with collecting tube6004. Rather, fluids are drawn through the production cylinders, first,then enter the production tube 2 through one or more common thief jets10. In one example, the several smaller orifices 6006 in the tube 6004serve to filter large particulates.

Examples of Gas Separation Operation.

In one example, a method for separating of gas from liquids in awellbore includes:

-   -   deploying a production pipe in the well bore, whereby a well        bore annulus is formed,    -   isolating formation fluids in the wellbore annulus at a vertical        location,    -   transporting isolated formation fluids (in one example, from        below the vertical location) to a chamber located above the        vertical location (e.g., in one example, the pressure loss        cylinder),    -   accumulating the transported isolated formation fluids in the        chamber,    -   separating, in the chamber, gas bubbles from the transported        isolated formation fluids in the chamber,    -   expelling the gas bubbles from the chamber into the wellbore        annulus above, whereby the transported isolated formation fluids        in the chamber become partially degassed,    -   jetting, below the expelling gas bubbles, the partially degassed        fluids from the chamber into the wellbore annulus,    -   drawing the partially degassed fluids from the wellbore annulus        into an upper portion of one or more isolated chambers (e.g., in        one example, production cylinders), the isolated chambers        positioned beneath the accumulating chamber, and    -   drawing, from a bottom portion of the one or more isolation        chambers, fluids into the production pipe through a jetting        port.

In a further example, the method for separating of gas from liquids in awellbore further includes reducing the rate of fluid flow into eachisolated chamber by stacking at least two or more isolated chambersvertically along the production pipe, each isolated chamber feedingfluids from a bottom portion through a jetting port into the productionpipe.

In a further example, the method for separating of gas from liquids in awellbore further includes isolating vertically each isolated chamberfrom each other, except by way of the jetted ports into the productionpipe and by way of drawing the partially degassed fluids from thewellbore annulus into an upper portion of each of the one or moreisolated chambers.

In one example, a method for separating of gas from liquids in awellbore includes:

-   -   deploying a shrouded production pipe in the well bore, whereby a        well bore annulus is formed,    -   isolating fluids in a lower section of the wellbore from the        wellbore annulus above,    -   accumulating a vertical column of the isolated fluids (in the        shrouded production pipe),    -   directing an upper portion of the accumulated vertical column of        the isolated fluids upward into an upper portion of a chamber        disposed above the vertical column of the isolated fluids,    -   directing a lower portion of the accumulated vertical column of        the isolated fluids upward into a lower portion of the chamber        disposed above the vertical column of the isolated fluids,    -   dumping the upper portion fluids into the top of the tool,    -   dumping the lower portion fluids into the top of the tool, below        the dumped upper portion fluids,    -   coalescing gases, in the chamber, from the dumped fluids,    -   accumulating partially-degassed fluids, in the chamber, from the        dumped fluids,    -   venting coalesced gases from the chamber into the wellbore, and    -   jetting partially-degassed fluids from the chamber into the        wellbore.

In a further example, the method for separating of gas from liquids in awellbore further includes collecting the partially-degassed fluids inthe wellbore into one or more second separation chambers (e.g., in oneexample, production chambers) disposed beneath the first separationchamber (e.g., in one example, the pressure loss cylinder), thepartially-degassed fluids entering an upper portion of each secondseparation chamber and drawing fluids from a bottom portion of each ofthe one or more second separation chambers through a port into theproduction pipe.

In a further example, the port into the production pipe is placedbeneath the one or more second separation chambers.

In a further example, the method for separating of gas from liquids in awellbore further includes where isolating fluids in a lower section ofthe wellbore from the wellbore annulus above comprises a longitudinallyflexible packer disposed in the wellbore annulus between the wellborewall and the shrouded production pipe.

In one example, a method for separating of gas from liquids in awellbore includes:

-   -   receiving wellbore fluids into two or more production separation        chambers, operating in parallel,    -   receiving production separation chamber fluids into a production        pipe through a thief jet port disposed in a lower portion of        each two or more production separation chambers, and    -   extracting bottom hole gas fluids in the wellbore from under the        two or more production separation chambers and disposing the gas        fluids back into the wellbore above the two or more production        separation chambers.

In one example, a method for separating of gas from liquids in awellbore includes:

-   -   receiving wellbore fluids into two or more production separation        chambers, operating in parallel,    -   receiving production separation chamber fluids into a production        pipe through a thief jet port disposed in a lower portion of        each production separation chamber, and    -   extracting bottom hole gas fluids in the wellbore from under the        two or more production separation chambers and disposing the gas        fluids back into the wellbore above the two or more production        separation chambers.

Conclusion.

Although the present invention is described herein with reference to aspecific preferred embodiment(s), many modifications and variationstherein will readily occur to those with ordinary skill in the art.Accordingly, all such variations and modifications are included withinthe intended scope of the present invention as defined by the referencenumerals used.

From the description contained herein, the features of any of theexamples, especially as set forth in the claims, can be combined witheach other in any meaningful manner to form further examples and/orembodiments.

The foregoing description is presented for purposes of illustration anddescription, and is not intended to limit the invention to the formsdisclosed herein. Consequently, variations and modificationscommensurate with the above teachings and the teaching of the relevantart are within the spirit of the invention. Such variations will readilysuggest themselves to those skilled in the relevant structural ormechanical art. Further, the embodiments described are also intended toenable others skilled in the art to utilize the invention and such orother embodiments and with various modifications required by theparticular applications or uses of the invention.

I claim:
 1. An apparatus for feeding well production fluids into a gas separator system, the apparatus comprising: a feed cylinder assembly separated vertically into an upper chamber and a lower chamber; a collecting tube extending into the upper chamber and the lower chamber; wherein the upper and lower chambers are partially isolated from each other by an annular ring, disposed between an outer wall of the feed cylinder assembly and the collecting tube, whereby a partial barrier is formed to control the vertical flow between the upper chamber and the lower chamber; an opening in the upper chamber, whereby fluids are fed into the gas separator system; an opening in the lower chamber, whereby well production fluids enter the feed cylinder assembly; an orifice in the collecting tube disposed in the upper chamber; and a plurality of orifices in the collecting tube disposed in the lower chamber, each of the plurality of orifices smaller than the orifice in the collecting tube disposed in the upper chamber.
 2. The apparatus of claim 1, wherein the opening in the upper chamber transports fluid to a pressure loss cylinder.
 3. The apparatus of claim 1, wherein small orifices or tube stubs are disposed in the annular ring.
 4. The apparatus of claim 1, wherein the plurality of orifices in the collecting tube disposed in the lower chamber are engineered to filter large particulates.
 5. The apparatus of claim 1, wherein the collecting tube is attached to a block that is attached to a production tube, whereby direct flow from the collecting tube into the production tube is prevented. 